A new insight into the electrochemical activation of passive graphene oxide by reversible anodic cycles: surface characterization and electrochemical properties.

A native graphene oxide (GO) prepared by Hummers' modified method was used as the template materials for the fabrication of electrochemically oxidative graphene oxide (OGO). The fabrication of OGO onto the glassy carbon electrode (GCE) persuaded via anodic reversible voltammetric cycles of a previously GO-GCE base surface materials. The new adapted approach was simple, cost-effective, and competent for producing active materials by preferential grafting of oxygenated functional groups into the GO lattice. It improved the rate of electron transfer process due to decreasing the contextual stacking among GO layers. The structure, composition, and the reactivity of the prepared OGO were characterized using various analytical techniques. FTIR data signified the richness of OGO surface with oxygenated functionalities including epoxy, ketonic, and carboxylic groups. The SEM images concluded a softer and smoother OGO surface, while the EDS analysis determines the significant differential amount of oxygen in OGO. XPS data confirmed the presence of a new oxygenated peak (not detected in the native GO) assigned to the aldehyde/alcoholic functional group. Cyclic voltammetric (CV) analysis of OGO-GCE in the background electrolyte indicated the existence of a couple reversible redox peaks. Differential pulse voltammetry (DPV) results were evident for the promising efficiency of OGO-GCE on the simultaneous determination of biological and environmental species such as dopamine (DA), ascorbic acid (AA), uric acid (UA), hydroquinone (HQ), and catechol (CC), respectively. [ABSTRACT FROM AUTHOR]